Aluminophosphate binders for various aggregates are known. Hacker, U.S. Pat. No. 4,303,450, discloses compositions for fireproofing steel structural members, which compositions comprise cement, perlite aggregate and bentonite; the dry composition is mixed with water in a nozzle mixer and sprayed onto the steel surface.
Shubow, U.S. Pat. Nos. 4,419,133 and 4,503,109, discloses bonded aggregate structures comprising alumina, magnesia, an aggregate such as sand or stone, and bonding agent comprising MAP also known as MALP (monoaluminum phosphate, Al(H.sub.2 PO.sub.4).sub.3).
Cassidy, U.S. Pat. No. 3,923,534, discloses slow setting castable compositions comprising magnesia, MAP and a refractory filler, and may also contain plasticizers when the composition is to be used as a ramming or gunning mix, e.g. bentonite and other clays or substitutes therefor, and clays may also be present to increase the hot strength of the product; foaming agents may also be present.
Russell, U.S. Pat. No. 4,262,055, discloses ammonium phosphate binders with a magnesia curing agent for light weight aggregates such as perlite. The aggregate binder mixture is applied as a light weight fire protection material to a structural member. Such mixtures have the drawback that the reaction between the ammonium phosphate and magnesia releases gaseous ammonia, which is unpleasant and hazardous for the workers.
Limes, U.S. Pat. No. 3,285,578, discloses refractory compositions comprising ammonium phosphate binders with magnesia, curing agent and aggregates which may be raw dolomite; the compositions may be in the form of gunning mixes.
Cassens, U.S. Pat. No. 4,276,091, describes refractory compositions containing alkali metal phosphate and aluminum salt binders for refractory aggregates. The compositions of Cassens is mixed dry and water is added to the dry mix in the nozzle of the gun prior to application to a surface.
Smith, U.S. Pat. No. 4,547,403, describes refractory compositions containing bulk fibers such as glass fibers, applied by spraying with a solution of high temperature resistant tacky binding material.
Vukasovich, U.S. Pat. No. 3,148,996, describes foamed ceramics made by reacting aluminum phosphate solution with calcium silicate to form a pasty product to which is added a gas or precursor therefor, such as fine particles of carbonate, followed by complete curing.
There is a need for a metallic coating or surface which may be applied and bonded to the surface of substrate structures, zone-confining panels, ceilings or walls, and the like, which coating can adhere indefinitely to the structures, be capable of facile application, especially brush or spray application, and cure or set up rapidly to a hard finish to provide good weather-proof, abrasion-resistant, reflective and/or electroconductive properties, an enhanced surface appearance, with patination if desired, and other desirable properties such as fireproofing or fire-resistant properties. The need for fireproofing is seen especially in areas where personnel are at risk in the event of a sudden fire where fire wall or heat differential protection is lacking for a sufficient time to enable the personnel to make a safe exit from the premises. There is a need for formed or molded dense-bonded conglomerate or monolithic structures that can be readily made and repaired by molding and can serve as tool pieces or dies for sheet metal forming or polymer resin injection molding.
It is therefore an object of the present invention to provide compositions for the bond-coating of substrate structures and means for their production which avoid the disadvantages of the prior art structures and processes.
It is also an object to provide dense-bonded conglomerate or monolithic structures having high early compressive strength and being useful as tool pieces or dies.
It is also an object of the invention to provide bonded surface-coated structures in any of a variety of architectural or decorative finishes, reflectivities, electronconductive formats, insulative and energy transfer qualities, fire resistant properties and the like.
It is another object of the invention to provide economical means for improving the thermal barrier efficiency of panel structures and the like as, for example, in furnaces, stoves, heaters, radiant heat panels, wall, floor and ceiling surfaces, building and room dividers, warehouse and storage spaces, heating and processing zones and the like.
It is still another object to provide means for the fast repair, retrofitting and/or construction of wear-resistant, insulative or fire-resistant surfaces, structures and the like, advantageously at ambient temperature.
These and other objects, features and advantages will be seen from the following detailed description of the invention.